Their house edge is caused by their rules and subtle things that are harder to notice...  The percentage point edge doesn't cause 20 losses in a row, that's just statistical probability.  In games of chance that rely on shuffling, rolling dice, etc., statistical probability basically realizes that everything will happen at some point.  You will get 20 losses in a row, you will get 20 wins in a row at some point, as long as you stay.  It's like pulling a blackjack followed by another.  It happens, it's statistically not often, but it does and will happen.  If you want to not get large loss-runs, then to decrease your chances, don't play as long.  That's how the house edge takes people.  If they have a 1% average, and you start with $100, their rules and games will result in taking $1 from that $100 every hour, on average.  Long sittings just increase your chances of the chance circumstances, both good and bad, of happening.  If you're wanting to make money, minimizing the chances of those occurrences is best. 

Where the edge comes from, in, say...  A BTC dice game is how they set the high/low and the bets.  Some of them display high as 5250 to 9999 and the low at 4750 down to 1.  High/low as a name gives the impression it's 50/50, but actually that would be a 0.95 chance of winning, not an even chance.  Just-dice cleverly uses decimals to distract people, >50.4999, <49.5000.  It's very distracting and misleading, subconsciously gives you the idea that it's one or the other, but you bet high, you get 50.4999 to 99.9999, whereas they get 0.0001 to 50.4998.  The button says <49.5000 but that's only for you if you click on low.  They get the edge from the extra 4 decimals' worth of number combinations that could be there.  I think that's actually a much higher edge on just dice than 1%.  Casinos, also, they use the 0 and 00 sections on Roulette that give them more than a 2% edge on people betting on the more straightforward one or the other bets.